BEIJING, Dec. 2, 2019 -- As Beijing embraced this winter's first snowfall on Friday, Zhou Bo, an HIV testing volunteer, was busy in his well-heated downtown office and unaware of the chilly weather outside.

"I have already received nine people today, and five more to be expected according to the reservation system." He said about 10 to 15 often show up during workdays, and 20 to 30 on Saturdays and Sundays.

The test lab where Zhou works belongs to a non-government institution of AIDS control and prevention in China, which also operates one of the country's biggest gay dating apps called Blued. Anyone can make a reservation with a testing room on the location-based app.

Blued has nearly 40 million registered users globally, with 60 percent in China.

Voluntary testing is an important part of AIDS prevention and control, in which online communities can play a big role, said Zhang Dapeng, vice president of the company's health sector.

"Blued's anonymous reservation and testing service can reach certain groups of people that are difficult to be reached through traditional means, and is more efficient and convenient," Zhang said.

Zhang used to work for the city's health and disease control department for years. He said Beijing has four such labs, which offered free testing for 8,000 people in 2018.

China has made significant progress in AIDS prevention and control, especially in recent years, said Gao Fu, head of the country's disease control and prevention center.

HIV infection via blood transmission has been almost eliminated, while infection among drug users through injection and mother-to-child transmission have been effectively curtailed.

Gao said the containment of transmission through sex has become the most important aspect of AIDS control.

In September, the Chinese government introduced a three-year plan from 2019 to 2022 to curb the spread of AIDS, in which the role of the internet was highlighted.

Blued mentioned in a report that its AIDS-related public service advertising reached over 130 million pop-ups on its App, received nearly 24 million views.

Zhang said the online testing reservation system has won support from related government departments. So far, over 90 AIDS-prevention organizations have entered the platform to carry out anti-AIDS advertising and intervention, networking nearly 200 HIV testing stations nationwide, building an "air testing room" that is just one tap away from app users.

"To protect privacy and prompt more people to take the test, one only needs to provide the last four digits of their phone number and can use a pseudonym," Zhou said. Only those with results tested positive are required to produce their ID cards for final confirmation from local disease control centers.

Zhou became a volunteer eight months ago when one of his friends was infected with HIV. Having no knowledge at all, he wanted to help but didn't know how.

"I've learned a lot here and helped a lot of people," he said.

According to the Beijing Municipal Health Commission, a total of 2,669 new HIV/AIDS cases were reported in the first ten months of this year in the city, down 7.1 percent year on year.

Since the first case in 1985, which was also the nation's first, Beijing had reported 32,268 HIV/AIDS cases as of the end of October, and 22,147 of them are still alive, the commission said.

The theme of the 2019 observance of World AIDS Day is "Communities make the difference."

Online communities should and must be an important part, especially in China, a country with a highly-developed mobile internet industry, Zhang said. "I believe the internet will play en even bigger role in HIV/AIDS prevention and control in China, offering more practical experience to the world," Zhang said.